无法扩展 'Ext.panel.Panel' 但可以 'Ext.tab.Panel'

Cannot extend 'Ext.panel.Panel' but can 'Ext.tab.Panel'

我期待延长 Ext.container.Container / Ext.panel.Panel 但我得到

Uncaught TypeError: Cannot read property 'substring' of undefinedExt.ClassManager.parseNamespace @ ext-all-debug.js:5054Ext.ClassManager.get @ ext-all-debug.js:5162Ext.ClassManager.instantiate @ ext-all-debug.js:5445Ext.ClassManager.instantiateByAlias @ ext-all-debug.js:5427Ext.define.statics.create @ ext-all-debug.js:35152Ext.define.getLayout @ ext-all-debug.js:37987Ext.define.initComponent @ ext-all-debug.js:37851Base.implement.callParent @ ext-all-debug.js:4263Ext.define.initComponent @ ext-all-debug.js:51597Base.implement.callParent @ ext-all-debug.js:4263Ext.define.initComponent @ ext-all-debug.js:54228Ext.define.constructor @ ext-all-debug.js:29554Base.implement.callParent @ ext-all-debug.js:4263Ext.define.constructor @ ext-all-debug.js:33592constructor @ ext-all-debug.js:4894(anonymous function) @ VM11877:3Ext.ClassManager.instantiate @ ext-all-debug.js:5482(anonymous function) @ ext-all-debug.js:2109(anonymous function) @ app.js:37

但另一方面它适​​用于 Ext.tab.Panel。 你能帮我确定为什么会这样吗?

Ext.define('Play.ground.labelinput.LabeledSlider', {
    //extend: 'Ext.tab.Panel',
    extend:'Ext.panel.Panel',

    alias: 'playground.LblSlider',
    bodyPadding: '10px',
    layout:{

    },
    items:[{
        xtype: 'label',
        //forId: 'sliderId',
        text: 'slider1'
    },{
        xtype: 'slider',
        width: 200,
        value: 50,
        increment: 10,
        minValue: 0,
        maxValue: 100,
        renderTo: Ext.getBody()
    }]
});

设置一个layout,不能为空对象